The instant invention relates to flush toilets and more particularly to a flush toilet which is adapted to operate with a minimal quantity of water.
In recent years water shortages have made it important to reduce water usage in many areas of the world. In this regard, it has been found that flush toilets often consume as much as 40% of the water supplied to domestic consumers and that as a result, the water used in flush toilets can represent a significant portion of the overall water usage in a particular geographical area. Consequently, a significant need has developed for an effective flush toilet which is capable of effectively operating with a minimal quantity of water.
While a variety of flush toilets have been heretofore available which have been adapted to operate with reduced amounts of water, it has generally been found that most of the heretofore available toilets of this type have been prone to causing blockages in sewer lines to which they are connected. In particular, it has been found that most of the heretofore available toilets which have been adapted to operate with reduced quantities of water (less than approximately two gallons) have been prone to causing blockages in sewer lines to which they are connected because they generally discharge waste materials into sewer lines at relatively low flow velocities which are insufficient to carry many solid waste materials into waste handling systems, such as septic tanks or municipal sewage facilities. It has been further found that this problem is compounded by the fact that most of the heretofore available flush toilets which have been adapted to operated with minimal quantities of water have discharged waste materials containing unmacerated solids which tend to cause blockages in residential sewer lines, particularly when they are discharged at relatively low flow velocities.
The instant invention provides a highly effective flush toilet construction which is adapted to overcome the sewer line blockage problems which have been experienced with the heretofore available flush toilets which have been adapted for reduced water usage. In particular, the toilet construction of the instant invention comprises a toilet unit including a bowl portion, an outlet portion defining an outlet passage which extends outwardly from the bowl portion, closure means for closing the outlet portion, and flushing means connectable to a supply of water for flushing the bowl portion and the outlet portion with a quantity of less than approximately one gallon of water. The toilet construction further comprises holding tank means having a waste inlet opening therein which opens into an interior holding chamber and discharge means which is connectable to a sewage pipe and actuatable for discharging waste from the interior holding chamber into the sewage pipe. The toilet unit is preferably received and supported on the holding tank means so that waste passing outwardly from the toilet unit passes downwardly through the outlet passage and into the interior holding chamber in the holding tank means. The holding tank means is constructed so that the interior holding tank chamber has a volume of at least approximately two one half gallons so that it can accommodate waste material from at least two flushes of the toilet unit before it is necessary to actuate the discharge means. Further, the holding tank means preferably has an interior bottom wall which is inclined downwardly and rearwardly at an angle of at least approximately 10.degree. and defines the bottom of the interior chamber. The holding tank unit preferably has a volume of less than approximately six gallons to enable it to be effectively accommodated beneath the toilet unit with the toilet unit supported thereon and the closure means of the toilet unit preferably comprises mechanical closure means which is selectively operable in a closed position for mechanically obstructing the outlet portion of the toilet unit and an open position wherein waste material from the bowl portion can gravitate downwardly and outwardly into the holding tank means. The discharge means preferably comprises a centrifugal pump including a housing having an impeller cavity therein and an impeller which is rotatable about a substantially horizontal axis of rotation in the cavity. The pump housing has an inlet opening therein which is preferably positioned so that substantially the entire cross sectional area thereof is offset downwardly from the axis of rotation of the pump. Accordingly, the centrifugal pump is operative as a macerator pump which is capable of macerating waste material from the holding tank means before it is discharged into a sewer line. The centrifugal discharge pump is preferably further positioned so that the inlet opening thereof is partially above and partially below the upper surface of the adjacent portion of the downwardly inclined bottom wall in the holding tank means. The discharge means preferably still further comprises a discharge pipe which extends upwardly from the centrifugal macerator pump to at least approximately the elevation of the waste inlet in the holding tank means and then downwardly to a point below the elevation of the macerator pump. Even still further, the macerator pump is preferably positioned adjacent to the rear end of the holding tank means so that it defines the rearmost extremity of the toilet and the discharge pipe preferably extends upwardly from the macerator pump and then downwardly to a downwardly facing circular discharge outlet which is spaced forwardly from the rearmost extremity of the macerator pump by approximately 12 inches.
It has been found that the toilet construction of the instant invention can be effectively utilized in most domestic applications without causing chronic clogging problems in a residential sewer line connected thereto. In this regard, it has been found that because the toilet construction of the instant invention includes a holding tank means which is operative for holding waste material from several flushes, waste material can be discharged from the toilet at a sufficient velocity to advance it through a residential sewer line without clogging. Further, it has been found that because the discharge means preferably comprises a centrifugal pump having an inlet opening which is offset from the axis of rotation of the impeller thereof, the discharge means is operative for macerating waste material from the holding tank means before it is discharged into a sewer line so that the potential for clogging problems is even further reduced. In addition, it has been found that because the discharge pipe from the discharge pump extends upwardly to approximately the height of the inlet opening in the holding tank means and then downwardly to an elevation below the centrifugal pump, a portion of the material from the discharge pipe flows back into the centrifugal pump and the holding tank means when the centrifugal pump is deactuated to provide a liquid seal between the holding tank means and a sewer line connected to the discharge line. Further, it has been found that because the centrifugal pump preferably defines the rearmost extremity of the toilet and because the outlet from the discharge pipe is spaced forwardly from the rearmost extremity of the centrifugal pump by approximately 12 inches, the toilet construction of the instant invention can normally be installed in place of a conventional domestic toilet without piping modifications. Still further, it has been found that because the holding tank means has a volume of between approximately two and one half gallons and six gallons and because the toilet unit is supported on top of the holding tank means, the toilet construction of the instant invention normally occupies approximately the same area as a conventional flush toilet. Even still further, it has been found that because the toilet unit is preferably adapted to discharge material substantially directly downwardly into the holding tank means and because the toilet unit preferably comprises mechanical closure means, the toilet unit is operable with a minimal amount of flushing water and it has been found that because the bottom wall of the holding tank means is inclined downwardly and rearwardly, waste material from the toilet unit can effectively pass downwardly along the bottom wall of the holding tank means to the centrifugal pump where it is macerated before it is discharged into a sewer line.
Devices representing the closest prior art to the subject invention of which the applicant is aware are disclosed in the U.S. patents to DEMAREST, U.S. Pat. No. 274,182; HAGUE et al U.S. Pat. No. 1,957,831; DIRKS et al U.S. Pat. No. 3,576,038; ALBERTASSI et al U.S. Pat. No. 4,131,959; TOBIN, Jr. U.S. Pat. No. 4,159,550; HENNESSY et al U.S. Pat. No. 4,407,025; BARNUM et al U.S. Pat. No. 4,498,203; DAVID U.S. Pat. No. 4,543,674; and HEINZE et al U.S. Pat. No. 4,672,689. However, these references fail to suggest the concept of providing a toilet comprising a toilet unit which is supported on a holding tank and discharge means for discharging waste material from the holding tank into a sewer line wherein the toilet unit is operative with a minimal quantity of flushing water and wherein the holding tank is adapted to contain waste material from several flushes in order to increase the volume of the waste material which is discharged into the sewer line at one time. The above references also fail to suggest many of the other more specific features of the toilet construction of the instant invention and hence they are believed to be of only general interest with respect thereto.
Accordingly, it is a primary object of the instant invention to provide an effective water saving toilet construction.
Another object of the instant invention is to provide an effective toilet construction comprising a toilet unit which is operative with a minimal quantity of flushing water and supported on a holding tank which is located directly beneath the toilet unit.
An even further object of the instant invention is to provide a water saving toilet construction wherein waste material is macerated before it is discharged into a sewer line.
An even still further object of the instant invention is to provide a water saving toilet construction comprising a toilet unit and a holding tank which is adapted to be installed in place of a conventional domestic flush toilet.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.